This invention relates to a cover intended for the protection of a machine bed and consisting of a plurality of cover boxes slidable telescopically into one another, of which the largest cover box is fixedly connected to a part of the machine displaceable on the machine bed, while the smallest cover box carries a locking mechanism by which the smallest cover box may be locked to the end of the machine bed or to the largest cover box.
Covers of the type mentioned above are used for example in machine tools in order to be able to utilize the entire length of a machine's bed for the moving part of the machine (for example its carriage). In one known construction of the type in question (DE-OS No. 16 02 806), the locking mechanism comprises a reversible two-armed lever which is carried by the outer end wall of the smallest cover box. One arm of this lever cooperates with a control surface and with a pair of stops which are carried by the machine carriage or by the largest cover box via an extension projecting into the vicinity of the abovementioned outer end wall, while the other arm of the lever cooperates with another control surface and with another pair of stops which are positioned at the end of the machine bed.